An aquatic weed called "floating hearts" is reportedly causing massive problems for waterway managers across southern Florida.

The Southeast Asian weed was discovered 10 years ago in an East Naples, Fla., retention pond after someone, officials suspect, emptied an aquarium or water garden into the pond, giving the weed its start.

Floating hearts have now been reported as far north as Fellsmere in East Central Florida, the Naples (Fla.) Daily News reported Monday.

"We're willing to try anything to kill that plant," Carlos Morales, a crew chief with the South Florida Water Management District told the newspaper.

He said most herbicides tried so far infiltrate the weeds' stems, but never reach the roots. An aquatic weed-killer called Sonar -- costing about $1,500-a-gallon -- is apparently the most effective chemical, but Sonar treatments of some canals have only been protective for two or three months.

Officials say the weeds' broad leaves grow into giant swaths of green carpet, shrouding native aquatic vegetation in darkness, shading them to death, The Naples Daily News reported, noting the stems can easily break apart during periods of heavy flow, clogging culverts and causing flooding.

Copyright 2006 by United Press International